A STUDY ON THE VERTICAL DISTRIBUTION AND POPULATION TRENDS OF RHIZOSPHERE NEMATODES OF BANANA

The most important nematodes on the Banana plantation of south China Agricultural University were reniform nematodes (Rotylenchulus reniformis),rhabditids (Rhabdictis spp.) and spiral nematodes (Helicotyleuchus dihystera).There were different trends on the vertical distribution of varide species of nematodes in the soil.Rhabdictid distributed mainly fron o-10cm and spiral nematodes from 11-20cm,but reniform nematodes from31-50cm.Reniform nematodes showed distinctly seasonal fluctuation.The highest population density of them occurred in early May and the lowest in laterFebruary.Population fluctuation was closely correlated with the accumulated temperature and soil moilture content.Rhabditids and spiral nematodes did not appear a distinct,seasonal fluctuations.